Cerebral palsy (CP) is the term used for a series of motor deficits resulting from an injury to an immature brain. The motor deficits of CP limit a child's ability to explore his or her environment, thereby hindering intellectual and social stimulation. This can have significant implications for the child's educational development, independence and quality of life. The long term goal of this work is to develop practical and effective therapeutic interventions to improve the ability of these children to explore their environment independently. One motor deficit that has been studied in children with CP is an inability to generate force (muscle weakness). Currently, weakness in children with CP has only been studied using maximum voluntary contractions; however, because most activities of daily living are performed at submaximal forces, these measurements may not adequately portray the motor deficit. In this work, we will characterize the ability of children with CP to regulate forces in the lower extremity with a particular focus on force modulation, timing, and coordination. Furthermore, we will develop and evaluate a novel force modulation training protocol intended to improve both single and multi-joint control in an attempt to produce functional gains during locomotion. [unreadable] [unreadable]